The present invention relates to gold jewelry and in particular, to the manufacture of unitarily formed articles of jewelry, which as cast are composed of discrete regions of gold of different colors.
The outstanding qualities of gold, including its attractiveness in color and brightness, have made it exceptionally valuable throughout history. For centuries, gold has been used as a decorative ornament in jewelry. Today, jewelry remains the largest single use for gold in all parts of the world. 8 ENCYCLOPEDIA BRITANNICA 273 (15th ed. 1984). Much of the gold used in jewelry is alloyed with another metal or metals. It is well known that different colors of gold can be formed by alloying gold with different metals. (See for example, E. M. Wise, Gold-Copper-Silver Alloys, in METALS HANDBOOK 1117 (Taylor Lyman ed. 1948)). Through the use of different alloys, it is possible to produce different gold colored articles of jewelry. More often than not, the articles of jewelry produced are monochromatic. However, the creation of polychromatic gold articles of jewelry is known. These articles are created by, first, producing individual monochromatic gold articles of jewelry, albeit of different colors, and then soldering these monochromatic articles together to create a polychromatic article of gold jewelry.
There are a variety of different processes used to produce jewelry. One such process is casting. The art of casting jewelry is centuries old. In particular, the use of investment casting (the "lost wax" process) to manufacture jewelry is well known. (See for example Sam Tour, Jewelry Casting, in METALS HANDBOOK 1098 (Taylor Lyman ed. 1948)). The lost wax process is especially desirable when manufacturing jewelry since it allows for the mass production of complex shapes that are difficult to produce by machining, permits the reproduction of fine detail, and minimizes the amount of hand finishing that is required.
Due to the perpetual popularity of gold in general, and in particular gold jewelry, there will always exist a need for original uses of gold in jewelry and novel processes by which to manufacture this gold jewelry so that the ultimate selection of gold articles of jewelry is continually enhanced, diversified, and improved.